DE 2404536 discloses a method of producing gas blacks having a low extractables content, wherein hydrogen-rich mixtures are used as carrier gas for the carbon black oil vapour, and the carbon black deposited on the cooling roll is collected. These gas blacks have an extractables content of less than 0.100% by weight.
Furthermore, WO 2005/033217 discloses unscreened, untreated carbon blacks, having a pH of less than or equal to 6.0, a residue on ignition of less than or equal to 0.1%, and a 5 μm sieve residue of less than or equal to 200 ppm. These blacks are produced by the method steps of removing the heat from the flame by thermal conduction and/or radiation, forming a thin gas boundary layer, and accelerating or expanding the flow formed by the flame and the boundary layer.
A disadvantage of the known blacks is the poor hue contribution in coatings applications.